blackchin

Short definition from Wiktionary

Noun

1. 1
   Any of several species of fish with a black jaw, especially
2. 2
   Any of several species of fish with a black jaw, especially: in the species of the family Neoscopelidae, particularly;
3. 3
   in the species of the family Neoscopelidae, particularly: A Pacific blackchin (Scopelengys tristis)